With the spread of portable devices and wearable devices, demand for an increase in the capacity of secondary batteries mounted on them and a reduction in the weight and volume of the secondary batteries has been increasingly growing. Meanwhile, because of optimization of electrical specifications such as efficiency, an SN ratio, and a standard in a memory, input/output, an analog circuit, and the like, there is a tendency that various kinds of voltages such as 2.5 V, 5 V, 7 V, 12 V, and ±6 V are required as voltages to be supplied to them. Under the present conditions, the voltage extracted from a battery that supplies a constant voltage is converted via a step-up, step-down, or step-up and step-down DC/DC converter into a voltage required by each circuit.
For example, Patent Document 1 discloses a semiconductor device incorporating a nonaqueous secondary battery.
Meanwhile, as for wiring in general electronic devices, the shortest wiring is not necessarily used for a power supply line so that interference is prevented. However, in switching at a high frequency, the inductance and the like of wiring inevitably increases and resonance occurs at a certain frequency; thus, it has been difficult to obtain a sufficient constant voltage property.